Means for controlling a production process



FIPBZIZ XR 194559795 Fla-12$ May 22, 1923. 1,455,795

L. LOGAN MEANS FOR CONTROLLING A PRODUCTION PROCESS Filed Dec. 20. 1920 Fig.1.

\ Lighi Sensifive CelL 5 i 5 7 8 v Q Q a 3 3 Fig.2. M 25 Fig.3. 1 Li M 3ens\nveCe\\ v g z 22 Source ohght Z4 fiource CK Light.

. lnven'for; I Uoyd Logan 4| fiymwaw Aflys.

I 'To all whom itmoy concern:

Patented May'22, f

.uurrso STATES morn ment, or rmsauaon, rmmsnvmm.

' IEARSIOB CONTBOIJJNG A PRODUCTION Application fled December 20, 1,920. mm, no. name I Be it known that I, Lnorn Looama citizen of the United States and' resident of Pittsburgh, county of Allegheny, State of Pennsylvania, have invented an Improve- .'character of the operation or process as cirfiiy invention as it be apparatus for efiectmg fine m meur ents I in Fig. 2.

ment in Means for Controlling Production ProcesseS, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawing representing like parts.

This invention relates to means for auto-' matically controlling various operations and it has particular reference to a controlling 15 means which is rendered operative by or through the use of radiant energy. I

, The invention is capable of a wide range of use and may be arranged to exercise a control over an operation or process by limiting the amount of production, or by stopping or starting machinery, or by varyingthe or by operating alarm or or in fact by accomplishof other operations which the operation or process cumstances vary, indicating devices, inflg a large variety a cot m some way in question.

In carrying out my invention I provide means whereby the carrying out of the operation will cause a variation in radiant energy, preferably radiant energy in the form of light, and I also rovide means responsive to such variations in the radiant energy to exercise the desired control over theoperation.

In order to give an understandin of my invention I have illustrated in the rawings in a more or less diagrammatic way severa devices embodying the invention and by which difierent processes can be controlled in difierent ways. Fig. l'illustrates my be a plied to exercising num r of rotations of given part so as to stop the shaft from rota when the desired number of rotations have 11 completed invention as it might a control over the be applied to exercise control over the liquid level in a tankin which livered and from which drawn. 1

' 3 a plan view of thedevice shown F' 4' is a dia mmatic view showing 1g gm embodied in an drawings,

and 6 are views showing be used without departing ition.

half rotation be brought a shaft. or other- 2 illustrates my invention might liquid is being tie-1 a is being with by comparison of light waves through the production of interference fringes. In these it is to .be understood that the light-proof cases over the optical parts are omitted for different embodiments of the invention.

In all the. above embodiments of the invention the radiant energy which is used is light ener but I wish to state that the invention is not limited to constructions in which the radiant energy is in the formiof light, as radiant energy in other forms may from the inven- The apparatus shown in Fig. is designed to exercise a control of some .sort over a rotating element such, for instance as a shaft.

This element is indicated at 1. and it may be any rotated part. In providing an arrangement for exercisin control over the rotations of a rotary e ement I provide means whereby the rotation of such element will cause variations in radiant energy and also provide a receiving elementresponsive to such variations whichoperates to exercise the desired control. In the apparatus shown in Fig. 1*the radiant energy 18 light emitted from a source of light 2 and the receiver which is responsive to varlations in light is a light-sensitive cell 3, such as a selenium cell. The variations in light energy may be produced by rotation of the el epge tj in various ways without depizrting from my invention. Merely as an i ustration I have shown the element 1 as provided with a element rotates the opening will at each onein line with the light 2 so that a ray of light will be projected through the aperture. The tsensit ve cell is situated so that the ray of light which passes through. the aperture 4 W111 be received thereby and with this arrangement the-cell Wlll be subjected to a ligh i p twice during each rotation of the element 1. This light, sensitive cell is connected in a circuit 5 having a battery or other source of electrical energy 6, therem and the circuit connects to a relay 7. Thai t sensitive I oell 3 is of such a character at the electrical resistance thereof varies as the amount of light to which the cellis sub ected varies and with this arranggnent therefore there will he variationsin t resistance in the arcuit 5 corresponding, thejrotations o the sake of clearness. Figs. 5-

ft w.

element 1. If the cell 3 is a selenium cell then the resistance in the circuit will decrease when the light ray is projected onto the cell through the opening 4 and will mcrease whenever the shaft is turned so as to cut off the light from the cell. At each onehalf rotation of the element 1 therefore the resistance in the circuit 5 will be momentarily diminished.

The relay 7 is arranged to close a second circuit 8 having a source of electricity 9 therein which is considerably greater than that in the circuit 5. This relay is constructed so that the resistance of the lightsensitive cell when the latter is not subjected to the light ray will be suflicient to prevent the relay from operating but when the selenium cell is subjected to the light ray projected through the aperture 4 then the resistance of the circuit 5 will be diminished sufliciently so that the relay will,

become operative to close the circuit 8. This circuit is shown as connected to a counting mechanism 10 which ma have any suitable or usual construction an which is arranged so that each time the circuit 8 is closed the counting mechanism will he stepped forward one step. This counting mechanism therefore will count the number of times that the circuit 8 is closed and this in turn depends upon the number of times the element 1 is rotated.

The use of a projection on the shaft to obstruct the light impinging on the lightsensitive cell once during each revolution is another modification within the scope of the invention. It is intended to apply the device in a similar manner to reciprocating parts.

The counting mechanism may be arranged to control some suitable devices, such, for instance, as a motor or driving mechanism which in turn controls the motion of the element 1 or of any element whose motion de ends on that of element 1. Merely as an il ustration I have shown a counting mechanism arranged so that after it has counted a certain predetermined number it will close a control circuit 11 which in turn operates a solenoid or magnet 12 that controls a stopping mechanism or any other device which will stop or affect in some way the rotation of the element 1.

With an arrangement of this sort therefore it would be possible to employ a counting mechanism which would become operative to open an operating circuit or perform some other act which would have the efiect of bringing the element 1 to rest afterit has made a predetermined number of revolutions.

In Figs. 2 and 3 I have illustrated another application of my invention by which it is used to exercise a control over the liquid level in a tank.

In this embodiment the tank is indicated at 13 and it is provided with an inlet pipe 14 and with a discharge pi e 15 from which the contents may he wit rawn. The inlet pipe 14 is shown as having a valve 16 therein.

17 indicates a hollow transparent prism which is connected to the tank 13 by the two pipe connections 18 and 19, said prism being arranged at substantially the desired liquid level in the tank. With this arrangement when the liquid level in the tank 22 having a relay 23 therein. This relay in turn controls an operating circuit 24 which has therein a solenoid or magnet 25 that controls the valve 16.

The arrangement of the source of light and the selenium cell and the prism is such that so lon as there is no liquid in the prism the light rays will pass through the prism but ,when the prism is filled with liquid the beam of light from the source of light will be deflected by the prism, due to total reflection onto the light sensitive cell 21, thus reducing the resistance of the circuit 22 and causing the relay 23 to operate to close the circuit 24.

hen this occurs the solenoid or magnet will be energized thereby closing the valve 16 and preventing further delivery of liquid into the tank.

When the liquid level in the tank falls below the prism so that the latter is emptied of liquid then the light will be withdrawn from the light sensitive cell and the relay will become inoperative thus allowing the valve 16 to open again automatically.

In this embodiment of the invention the radiant energy deflected by the prism 17 is made use of to exercise control over' the liquid level in the tank.

In Fig. 4 I have illustrated diagrammatically still another embodiment of my invention which involves the use of a socalled interferometer by which interference fringes may be produced. The type of interferometer shown .involves a source of light 26 and a glass plate 27 which is thinly coated on one side with silver and is arranged to receive the beam of light 28 at an angle of degrees. The thickness of the coating of silver is such that one-half of the light is reflected as shown at the dotted line 29 and one-half is refracted along the line 30. 31 and 32 are two mirrors or other reflectors one of which is situated at right angles to the reflected beam of light 29 and the other of which is situated at anglesto the refracted beam' flected from the mirror 32 as shown at 33 and a portion of the light reflected by the mirror 31 is refracted by the plate 27 so that both this refracted light and reflected light form a single-beam indicated at 33. 34 is a screen receiving this beam and'is provided with a slit 35. -Assuming that the beam of light 28 is of one color, for instance a red color and that the mirrors 31 and 32 are exactly the same distance from the glass plate 27 then the light waves of the two beams 33 will be in phase and each will augment the other; but if the mirror 31 for instance is a greater distance from the glass plate 27 then the mirror 32 by an amount equal to one-half the wave length of the red light wave then the waves of the two beams at 33-will be in opposite phase and will neutralize each other thus producing total extinction of ligth due to the interferenceof the light waves. Again if the mirror 31 is given a still further movement so thatitsdistance from plate 27 is greater than that ot themirror 32 by an amount equal to one, two, three or any number of wave lengths of the red light rays, then the waves of the two beams will be 1n phase again at the screen and light will exist at this point. Hence if it be assumed that the mirror "32 is stationary and the mirror 31 is gradually moved awav from the plate 27 alternate 'lieht and darkness will be produced at the slit 35, the change from light to darkness representing a movement of the mirror 31 equal to one-half of the length of a wave of red light. The red light wave length is about 1/30,000 of an inch and therefore with such an a partus using red light each movement 0 the mirror 31 through 1/60,000 of an inch will produce a change from darkness to light or light to darkness at the slit 35. a

In using an apparatus of this type .for

carrying out my invention-I would place a' light sensitive cell 36 adjacent the slit 35 to receive light there through, said slit being connected in a circuit 37 having a "re-I lay 38 therein adapted to close an operating circuit 39. TlllS operating circuit may be arranged to actuate any desired apparatus for I exercising the desired control. One such apparatus would be a counting mechanism 40 whichis actuated by succes- -sive impulses in the circuit 39 and. the

counting could be arranged to close the circuit 41havinggsonie control device therein which operative cRoss REFERENCE 'this case a microscope 43 might be mounted on the mirror 31 and the latter positioned so that the cross hairs of the microscope would be focussed on one end of the object 42. The counting mechanism would then be connected into the circuit and the mirror.

moved by means of a screw 44 or any other suitabledevice so that the cross hairs of the microscope would be focussed on ,the

opposite end of the object 42. Such movement of the mirror would produce alternate light and darkness at the slit 35 re-' sulting in subjecting the cell to alternate light and darkness and this would operate as above described to actuate the counting mechanism. The number of impulses given to the counting mechanism by the movement of the microscope from one end of the object 42 to the other would give the dimension of the object 42 inwave lengths of the particularlight being used. Supposing for illustration that the indicator indicated 10,000 wave lengths and if the light being used is a red light of 0.00082 millimetres wave length these 10,000 wave lengths would indicate a dimension of 0.82

centimeters.

Another way'of using this device-would be for the purpose of securing accurate dimensions in a piece of optical glass or other material being polished or operated upon in some machine. For instance if a piece of lass, such as an interferometer plate is ing ground by a machine to, secure very accurate dimensions then the mirror 31 or a projection extending therefrom might be arranged to make contact with such piece at intervals, at the same time atuomatically arresting the motion of the machine. In this case the counting mechanism could be arrangedto close the circuit containing the control mechanism when'the desired dimension is approached thus stopping the operation of the ma'chineor operating an alarm.

When the material being worked on has the required reflectin properties suitable provisions may be ma e to use such a part in 'a similar manner to the mirror 31, the

'difierent' uses to which the invention may be EMMlNER I III , cause variations therein by the quantity proput a'ndthat they are not intended in any way as setting up limitations for the invention.

I claim:

1. The combination with means for produclng radiant energy, of other means to duced in a process or operation in ich material is acted upon, and means rendered operative by said variations to exercise control over said rocess or operation.

'2. The combination with means for producing radiant energy, of other means to cause variations therein by the quantity roduced'in a process in which a material is acted upon and which is independent of the means for producing said radiant energy, and means rendered operative by said variations when a predetermined quantity has been produced to exercise control over the process.

3. The combination with means for producing radiant energy, of other means to cause variations therein by the quantity roduced in a production process which is independent of said means for producing radiant energy, and means responsive to such variations to give a measurement of production.

4. The combination with means for producing radiant energy, of other means to cause variations therein by the quantity produced in a process in which material is acted upon and which is independent of said means for producing radiant energy, and means responsive to said variations in radiant energy to perform a predetermined function.

5. In a device of the class described, the combination with means for producing radiant energy, of other means to cause variations the'rein b variations in quantity or amount involve in a process in which material is being acted upon, which is independent of the means for producing radiant energy, of an element controlled by said variations in radiant energy and adapted to respond in a predetermined degree to such variations in quantity or amount.

In testimony whereof, I have signed my name to this specification.

LLOYD LOGAN. 

